Journal: International Journal of Molecular Sciences
Article Title: Examination of Intracellular GPCR-Mediated Signaling with High Temporal Resolution
doi: 10.3390/ijms23158516
Figure Lengend Snippet: Stopped-flow experiments with flpTM-DmOctβ1 cells loaded with Fluo-4. Fluo-4-loaded flpTM-DmOctβ1 cells were stimulated in stopped-flow experiments with increasing octopamine ( A ) and NKH477 ( B ) concentrations. Fluorescence intensities were monitored over 80 s and 100 s, respectively. Fluorescent changes (ΔF/F 0 ) for each octopamine and NKH477 concentration were calculated and plotted over time ( A1 , B1 ). To resolve signal response times, the initial 35 s and 40 s of each measurement are displayed ( A2 , B2 ). Shown are representative measurements from three independent datasets. Each data point was obtained from triplicate measurements; ( C ) Concentration–response curves were generated by plotting maximal changes in fluorescence against octopamine (green) and NKH477 (red) concentrations. Maximal changes in fluorescence at the highest ligand concentrations were normalized to 100% and EC 50 values were obtained from nonlinear fitting of the data using GraphPad Prism v5.04. Shown is a representative concentration–response curve from three independent datasets. Mean EC 50 values are indicated; ( D ) Bar graph showing the time until signal was detected at concentrations in the range of EC 50 values (dynamic range) and at saturating concentrations (saturating range) for octopamine (green) and for NKH477 (red). Each data point was obtained from triplicate measurements. Shown are mean values ± SEM from three independent datasets.
Article Snippet: The EC 50 values were determined from a nonlinear regression plot (four parameters) using GraphPad Prism v5.04 for analysis and display.
Techniques: Fluorescence, Concentration Assay, Generated